Intrinsic factor

Definition

Intrinsic factor is a protein produced by cells in the stomach lining. It is needed for the intestines to absorb vitamin B12efficiently.

In a disease called pernicious anemia, immune system damage to the stomach lining can cause a lack (deficiency) of intrinsic factor. Pernicious anemia causes vitamin B12 deficiency, which leads to a low red blood cell count (anemia).

Intrinsic factor deficiencies can also be caused by other reasons, such as:

• Inherited conditions
• Other diseases
• Surgical removal of the stomach

Antony AC. Megaloblastic anemia. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 170.

Antony AC. Megaloblastic anemia. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 39.